Let x represent the number of weeks he needs
Given that he can save $30 per week, it means that in x weeks, he can save $30x
We were also told that he already has $40. This means that the total amount that he has afterx weeks is
30x + 40
Given that Tim is trying to save $160 to buy a new gaming system, it means that the amount that he need is greater than or equal to $160
Thus, the inequality representing this situation is

After 4 weeks, he will have enough money.